Printing pressure device for alcohol duplicators



March 2, 1954 CORONA 2,670,678

PRINTING PRESSURE DEVICE FOR ALCOHOL DUPLICATORS Filed March 21, 1951 INVENTOR 1e ANTONIO CORONA ATTORNEYS Patented Mar. 2, 1954 UNITED STATES PATENT OFFICE PRINTING PRESSURE DEVICE FOR ALCOHOL DUPLICATORS 3 Claims.

It is an object of the present invention to provide an alcohol duplicator comprising a casing, a roller carrying the original and rotatable in said casing and a printing roller adapted to operate with the first roller, supported on its pins in a rotatable manner too by levers fulcrumed in said casing, characterized in that said levers rest at their free ends on cams fitted on a single spindle operable by the operator, the cams having as a profile a segment of Archimedean spiral, the ends of which are joined radially.

In the accompanying drawing there is illustrated merely by way of example the preferred embodiment, viz:

Fig. 1 is an elevational view, partly in section, of the part of duplicator to which the invention relates; and

Fig. 2 is a plan view thereof.

With reference to the drawing, l designates the side frames of the casing, 2 the matrix-carrying roller journaled on said frame, 3 the printing roller, rubber-coated, supported pivotally by the levers fulcrumed at 4 to the side frames l Each of said levers comprises a rigid part 5 and a resilient part l3; the rigid part 5 is terminated at the free end with a fork 6, the branches of which support the horizontal pin 1; in said fork is screwed a screw I l the axis of which is situated in the plane of oscillation of the lever. The resilient part I3 is constituted by a resilient lamina which at one end rests on a cam l 4 and at the other end If! rests on the head of the screw l I, after forming a loop receiving the pin 7 in such a manner that between the supports at the ends and the pin 1 a clamping action is established, by which the pin 1 prevents the lamina l3 from being released by the supports.

The profile of the cam I4 is constituted by a segment of Archimedean spiral a -b the ends of which are radially joined to each other. The two cams [4 are fitted onto one single spindle l 5 controlled by means of a graduating knob 16 provided at the side frame of the casing, externally thereon.

For the sake of completeness, 11 indicates the oval bushes by way of which the pins of the printing roller rest on the lever 5.

The embodiment described offers the following advantages:

((1) By turning by hand the spindle l5 and thus the cams, it is possible to obtain, thanks to their profile, a micrometric adjustment of the printing pressure in such a manner as to utilize gradually the ink of the matrix to obtain the largest possible number of copies. At the same time, it has been assured that on reaching the maximum pressure, the pressure returns to nil automatically and instantaneously in order to avoid the danger of injuring the printing roller by keeping it under pressure;

(b) It permits a self-adjustment of the line of contact between the printing roller and the matrix-carrying roller, because the pressure is obtained by way of resilient laminae and the printing roller turns on oval oscillating bearings;

(c) It encloses in a small space an assembly sufiiciently compact that the strong printing pressure is put in register with one single turn of the knob.

The adjustment of alignment of the two printing rollers is obtained by means of the two screws II with a counter nut, and it varies the angle between the arts of each lever.

Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed, I declare that what I claim is:

1. A duplicating printer comprising a frame, a I

roller for the material to be printed and rotatably journaled in the frame, a lever pivotally mounted at one end on each side of the frame beneath the roller, a journal bearing carried by each lever, a printing roller mounted in said bearings for cooperation with said first mentioned roller, an adjustable shaft and a pair of cams on the shaft for supporting the other ends of the levers.

2. A duplicating printer comprising a frame, a roller for the material to be printed and rotatably journaled in the frame, a lever pivotally mounted at one end on each side of the frame beneath the roller, a journal bearing carried by each lever, a printing roller mounted in said bearings for cooperation with said first mentioned roller, each lever having a resilient free end, an adjustable shaft and a pair of cams on the shaft for supporting the resilient ends of the levers.

3. A duplicating printer as defined in claim 2 in which means are provided on each lever to hold a resilient free end from disengagement.

ANTONIO CORONA.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,466,873 Avery Apr. 12, 1949 2,518,878 Gerlach Aug. 15, 1950 2,563,403 Ford et al Aug. 7, 1951 FOREIGN PATENTS Number Country Date 580,577 Great Britain Sept. 12, 1946 

